app/django/utils/_os.py
author Pawel Solyga <Pawel.Solyga@gmail.com>
Wed, 20 Aug 2008 21:59:00 +0000
changeset 98 b2b823466a8b
parent 54 03e267d67478
child 323 ff1a9aa48cfd
permissions -rw-r--r--
User Profile view (without controller yet). Patch by: Pawel Solyga Review by: Todd Larsen Review issue: 386 Review URL: http://codereviews.googleopensourceprograms.com/386
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from os.path import join, normcase, abspath, sep
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def safe_join(base, *paths):
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    """
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    Joins one or more path components to the base path component intelligently.
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    Returns a normalized, absolute version of the final path.
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    The final path must be located inside of the base path component (otherwise
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    a ValueError is raised).
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    """
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    # We need to use normcase to ensure we don't false-negative on case
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    # insensitive operating systems (like Windows).
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    final_path = normcase(abspath(join(base, *paths)))
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    base_path = normcase(abspath(base))
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    base_path_len = len(base_path)
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    # Ensure final_path starts with base_path and that the next character after
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    # the final path is os.sep (or nothing, in which case final_path must be
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    # equal to base_path).
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    if not final_path.startswith(base_path) \
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       or final_path[base_path_len:base_path_len+1] not in ('', sep):
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        raise ValueError('the joined path is located outside of the base path'
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                         ' component')
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    return final_path